Applicants' invention is directed to a test fixture for maintaining the temperature of a device under test within predetermined limits when said device is subjected to a relatively sizeable amount of electrical energy for test purposes.
Numerous structures and techniques have been employed in the art for the cooling of electronic devices including semiconductor devices. The structures of the prior art are extensive and varied. Many of the structures of the prior art employ a liquid coolant. Particularly, well-known to the art and commonly employed is a heat sink fabricated from a metal, such as copper, having the ability to efficiently conduct energy in the form of heat. Many of these heat sinks have provision for passing a coolant liquid through the heat sink for maintaining the heat sink within a predetermined temperature range.
It is also well-known in the art to submerge an electronic component or device in a suitable coolant liquid. It is also well-known in the art to provide control apparatus for controlling the flow of coolant in a heat sink or bath.
In U.S. Pat. No. 3,007,088, granted to E. J. Diebold on Oct. 31, 1961, a rectifier such as a crystal junction rectifier utilizing a germanium or silicon wafer as a rectifying medium, is clamped to a fluid-cooled bus bar. A heat-conductive and electrically conductive grease, for example silicone grease, is provided between the lower base block (lower cathode contact) and the liquid cooled bus bar. The silicone grease under pressure fills voids which may exist between opposing surfaces which are not perfectly smooth. Heat transfer from the base block to the bus bar is thereby improved by virtue of the direct contact of the grease with portions of opposing surfaces which may not otherwise make direct contact. The tightening down of flanges by means of bolts puts the grease under high pressure.
In U.S. Pat. No. 3,648,167, granted to D. R. Purdy et al. on Mar. 7, 1972 fluid cooled apparatus for testing power semiconductor devices is disclosed. The apparatus includes a base member having a major surface and a cavity within the base member. The surface of the base member has an aperture which communicates with the cavity. The apparatus further includes means for holding the power semiconductor device in the aperture, so that an outer heat transfer surface of the device is exposed in the cavity. Additionally, the apparatus includes means for circulating a fluid through the cavity and across the heat transfer surface; and means in the cavity for controlling the circulating fluid so as to minimize the thermal resistance between the fluid and the heat transfer surface.
In U.S. Pat. No. 3,492,535, granted to D. L. Behrendt on Jan. 27, 1970 entitled "Ceramic Circuit Card", a thermally conductive compound is employed between the surfaces of the ceramic circuit card and the modules mounted thereon. The circuit card is comprised of an alumina ceramic substrate card with a multilayer pattern of conductors on one surface and a conductive plane on the opposing surface. Pads formed on circuit sites by increasing the lateral dimension of a conductor, are connected by the conductive pattern and a conductive layer about the edge of the substrate card to the plane on the opposing surface. The heat from the thermal emitting circuit modules mounted on the pads with a conductive thermal compound therebetween, is circulated away from the modules by the connecting path.
In U.S. Pat. No. 3,842,346, granted to C. R. Bobbitt on Oct. 15, 1974, entitled "Continuity Testing of Solid State Circuitry During Temperature Cycling", water is used to cool the heat sink for the thermoelectric devices. The thermoelectric devices are formed as flat plates which are assembled to be individually replaceable and are capable of cycling in two minutes or less from approximately 25.degree. to 100.degree.C and back to 25.degree.C.
In U.S. Pat. No. 3,761,808, granted to R. B. Ryan on Sept. 25, 1973 entitled "Testing Arrangement", the temperature of a device under test (packaged integrated circuit) is controlled by controlling the temperature of the fluid bath in which the device under test is submerged.
In U.S. Pat. No. 3,150,021, granted to A. Sato on Sept. 22, 1964, entitled "Method of Manufacturing Semiconductor Devices", the desired characteristics of a tunnel diode are achieved by manufacturing the tunnel diodes with a slightly oversized junction area. The tunnel diodes are then placed in a chemical etching bath which etches away edges of the junction area while simultaneously measuring the capacitance across the junction.
In U.S. Pat. No. 3,794,912, granted to P. J. W. Severin et al. on Feb. 26, 1974, entitled "Contact Device Using Conductive Fluid Measuring Resistance and Capacitance of Semiconductor", a liquid electrical contact is made with a semiconductor disk by forcing the liquid through an opening contained in the structure on which the disc is supported.
In U.S. Pat. No. 3,803,489, granted to G. L. Miller on Apr. 9, 1974, entitled "Liquid Contacts for Use in Semiconductor Profile Analysis", semiconductor doping profile apparatus of the type using current feedback for maintaining a constant modulation parameter is disclosed. Non-destructive analysis is achieved by using a liquid electrode rectifying contact for forming each required diode region. A metal electrode contacts the electrolyte and is surrounded by an annular guard ring maintained at rf ground, which defines precisely the area of the diode region.
U.S. Pat. No. 3,811,182, granted to W. J. Ryan et al. on May 21, 1974, entitled "Object Handling Fixture, System and Process" and of common assignee with the instant application, discloses vacuum controlled chip handling apparatus.
In the IBM Technical Disclosure Bulletin publication, entitled "Cooling System for an Integrated Circuit Tester", by R. C. Chu et al., Vol. 13, No. 11, April 1971, page 3547, a test chuck is provided into which the component to be tested is loaded. A reservoir is connected to the chuck by conduits. The reservoir can be raised and lowered. When the reservoir is raised, the liquid level is raised above the chuck so that the fluid fills the chuck by gravitational flow and provides the boiling type cooling for the electronic component located therein.
In the IBM Technical Disclosure Bulletin publication, entitled "High-Temperature Chip Handler" by M. J. Mulligan, Vol. 14, No. 4, September 1971, a conduction heated vacuum pencil is disclosed for incorporation into a chip handler for preheating semiconductor chips.
In the IBM Technical Disclosure Bulletin publication, entitled "Test Chamber with Seal and Boot", a test chamber used in testing substrates populated with integrated circuit chips is disclosed. The testing takes place in a liquid cooled environment to prevent device burnout and to minimize the possibility of contaminating the product and the coolant liquid.